High cholesterol is a major risk factor for coronary artery disease, the nation's top killer. But a growing body of research shows that this fat-like substance in your blood is just the tip of the iceberg. Scientists have learned that other substances may help your doctor predict your risk for heart disease.
Even if you do not have coronary artery disease, these predictors can provide a more complete and aggressive plan for reducing your chance of developing it. Currently, your risk of coronary artery disease is based on measuring LDL ("bad") cholesterol and HDL ("good") cholesterol. If your levels of HDL and LDL are abnormal, testing these additional predictors could influence the decision for more intense treatment.
If you already have heart disease, discuss appropriate treatment with your health care provider.
Potential new predictors
Triglycerides are a molecule made of glycerol and 3 fatty acids that transport fats and sugars in the body. They are no longer the new kid on the block, but many people still don't realize their importance. Triglycerides are your body's most common form of fat and the main source of stored energy. Your liver makes triglycerides and cholesterol from food. Doctors view high triglyceride levels as a warning sign.
Diet and exercise affect triglycerides, just as they do cholesterol. Obesity, inactivity, and high-sugar foods can cause special trouble. If lifestyle changes, like a low-fat diet and exercise, don't lower triglycerides, drugs, such as statins and fibrates, may help. In addition, the vitamin nicotinic acid, a specific form of niacin (also known as vitamin B3) may be used. Other forms of niacin do not affect triglyceride levels. Labs check triglycerides as part of a full lipid study that also measures HDL and LDL. Talk with your doctor if your level is high.
C-reactive protein (CRP) is a normal blood protein. CRP levels rise anytime there is inflammation in the body. However, scientists have found that if your CRP levels are high all the time, this often predicts inflammation and damage to blood vessels. The American Heart Association does not recommend checking everyone's CRP level, though. For people with an intermediate risk for heart disease, however, a CRP level may help a doctor decide whether to be more aggressive with treatment to reduce or eliminate risk factors for heart disease. Levels above 3 are considered high. Studies show statins (a class of medicines prescribed to lower cholesterol) may lower CRP.
Lipoprotein a (Lp(a))
Lp(a) is a fat-carrying particle made up of LDL and protein and is a genetic variation of normal LDL. A high level of Lp(a) is a risk factor for developing premature atherosclerosis. Scientists agree that your Lp(a) level is set mainly by genetics, so people with a family history of heart disease may have high levels. Knowing this may help doctors decide how aggressively to treat other risk factors, such as high LDL cholesterol.
Like high cholesterol, high Lp(a) levels can also be treated with statin drugs and niacin, but doctors don't yet know if lowering your Lp(a) level cuts your heart-disease risk. Your doctor would likely order an Lp(a) blood test only if you have other serious risk factors for heart disease. Other tests continue to be studied and may also prove to be predictors of heart disease. These include apolipoproteins, non-HDL lipoprotein and LDL sub-classes.
Cholesterol: Still the top danger sign
A high level of cholesterol in the blood is still the top heart disease predictor. The National Heart, Lung, and Blood Institute makes these recommendations for screening and treatment:
If you are 20 or older and of average risk for heart disease, you should have a full lipid profile at least every five years. This test is done after fasting and measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. LDL is the lipoprotein that carries the form of cholesterol that builds up in the arteries. HDL is the lipoprotein that carries cholesterol that is being removed from the body, which keeps it from building up on the walls of arteries
Doctors should treat certain people at risk more aggressively with drugs. The LDL level at which treatment with drugs is advised depends on whether you have other risk factors. People with two or more of the following risk factors are considered at higher risk:
An HDL below 40 mg/dL
High blood pressure
A family history of early heart disease (an immediate family member with heart disease before age 55 if a man, or before 65 if a woman)
Age (45 or older if a man, or 55 or older if a woman)
Arterial disease in your aorta, carotid arteries, or peripheral arteries
Having metabolic syndrome—a combination of abdominal obesity, high triglycerides, low HDL, high blood pressure, and a high blood sugar level
If you're at risk for heart disease, important lifestyle changes are needed. Cut saturated fats to 7 percent of your total daily calories, lower cholesterol in your diet to less than 200 mg a day, eat more soluble fiber and foods with plant stanols or sterols (found in some margarines and salad dressings), stick to a healthy weight, and make exercise a habit.
Also be sure you understand your risk level. Experts have set up four risk categories. Your doctor can work out your level with a risk assessment tool based on blood tests, blood pressure, and history of smoking.
Below 200 mg/dL
Above 60 mg/dL
Below 100 (depending on other risks) mg/dL
Below 150 mg/dL
*Do not eat or drink anything but water for 9-12 hours before cholesterol tests.